Nearly two and a half years have passed since 64-bit processors started going into PCs. But the software to take full advantage of these chips remains scarce, and customers aren't buying much of what's out there. The 64-bit chips provide greater performance than their older 32-bit counterparts, but that's because of speed upgrades and other architectural enhancements.

Except for a few workstation users, almost no one is getting much from the 64-bitness of these computers.

"Sixty-four bit is sellable as bigger, faster, but in terms of what it does for you, there is very little at the moment," said Roger Kay, president of analyst firm Endpoint Technologies Associates.

The dearth can be seen in a lot of ways. Microsoft released a 64-bit version of Windows for desktops last May but has sold few copies, according to analysts. A site created by Advanced Micro Devices, the biggest proponent of 64-bit desktops, lists only six games tweaked for 64-bit computing and one partial upgrade.

Dell sells 64-bit Windows as an option on two workstations and on a corporate desktop, but not on notebooks or any consumer PCs. Hewlett-Packard sells it as an option on workstations only. Lenovo offers it if a customer requests it. Gateway doesn't offer 64-bit software on its PCs with 64-bit chips at all.

Instead, most PC makers and software developers will wait until Vista, the next version of , comes out before starting to tackle the 64-bit conversion. Vista, which will run 32- and 64-bit applications, will probably start to appear on PCs during the holidays at the end of the year, but 64-bit software will emerge gradually. That means, however, that 64-bit applications won't likely start appearing in numbers until 2007 and 2008.

"There is just not enough driver support for 64-bit Windows," said Rahul Sood, president of Voodoo Computers. "We don't offer it. We are waiting for Vista."

The slow emergence of a 64-bit ecosystem also means that those consumers who bought 64-bit systems in the past few years to "future proof" themselves against a software conversion really didn't. By the time Vista comes out, those early 64-bit computers will be 3 years old, closing in on the typical four-year replacement cycle.

Most desktops and notebooks, in fact, can't even be upgraded to take full advantage of 64-bit computing. One of the main benefits of 64-bit computing is that a computer can store data in more than 4GB of memory. A few gamer-centric PC companies sell PCs and workstations that can accommodate more memory than that, but most don't. Most max out at 2GB. (There are some performance benefits to running 32-bit software on 64-bit chips, but the primary advantages emerge when 64-bit chips are matched with 64-bit software.)

Workstations from HP, Dell and others often accommodate at least 8GB of memory. Several workstation applications have been ported over, said Margaret Lewis, director of commercial solutions at AMD. Workstations, however, constitute a small market, and sales of workstations with 64-bit chips from AMD or Intel and of 64-bit software comprise only a fraction of that market. (Servers are a different story: Applications were ported to 64-bit platforms years ago, though one executive at Sun Microsystems said in July 2005 that only about 30 percent of customers had started running 64-bit software on its Opteron servers.)

"The reality is that it is tough to get your hands on that product. The big blocker is that there is no (consumer) app that demands that kind of power."

--Mike Cherry, analyst, Directions on Microsoft

The absence can mostly be explained by software delays. The 64-bit Windows was delayed a number of times, causing interest among developers and consumers to drop off. Epic Games put out a free 64-bit patch on its Web site for its game "Unreal Tournament" in 2004, but the uptick has been slow.

"I don't have usage statistics, but I expect they're pretty minimal," Tim Sweeney, founder of Epic, wrote in an e-mail. "Those OSes aren't ready for prime time because of a lack of drivers, application install problems and other random things. Real-world adoption of 64-bit OSes will probably only occur when Windows Vista ships."

A Microsoft representative wrote in an e-mail that the company has trained more than 300 developers on porting their applications to 64-bit Windows and that sales of the operating system have exceeded the company's expectations. The initial expectations, however, weren't revealed.

"The reality is that it is tough to get your hands on that product. The big blocker is that there is no (consumer) app that demands that kind of power," said Mike Cherry, an analyst at Directions on Microsoft. "There are also concerns about the availability of drivers."

Cherry, incidentally, said he bought a 64-bit laptop the other day but couldn't get one with 64-bit Windows.

Memory prices remain an issue, too. Historically, PC makers let memory account for 8 percent or less of the total price of a PC. Right now, 4GB of memory costs about $330, judging by current market prices. Although computer makers get volume discounts, that would still push the memory price tag past the usual bar.

When Vista hits, consumers will begin to see some 64-bit benefits, even if their applications remain 32-bit, according to AMD's Lewis, but 64-bit applications may not
start hitting in numbers for consumers until 2007 and 2008.

"You have to make sure you have the market to sell the code," she said.

In all fairness, AMD, the biggest proponent of 64-bit desktop computing, didn't expect an overnight revolution. The performance benefits of Opteron and Athlon initially would come from HyperTransport, an input-output standard, and an integrated memory controller, executives said in the years leading up to Opteron. Those two architectural changes did give Athlon and Opteron a boost in benchmarks.

Besides, the 64-bit discussions served a purpose in forcing Intel to finally come out with similar chips. It also allowed AMD to position itself as a technological leader. Since the release of Opteron and Athlon, it has gained market share.

Still, the changeover seems to be occurring slower than they anticipated. In 2002, AMD executives predicted that people would begin to start taking advantage of the 64-bit capabilities soon after the chips hit and that the market would begin to see some desktops with 4GB of memory in 2004.

In August 2003, before more Microsoft delays, AMD said 64-bit technology, including software, would be somewhat widespread in 12 to 15 months, even in notebooks.

Ironically, the 2007 and 2008 predictions for the emergence of 64-bit applications fit closer to what Intel said, before it jumped into 64-bit desktop chips. Company executives and scientists through 2002 and 2003 said mainstream users wouldn't likely need 64-bit desktops until about 2008 or 2009.